The interdisciplinary team represented herein proposes continued research aimed at understanding the molecular pharmacology of currently used general anesthetics. The team has evolved from simple peptide models in previous cycles of this program to now study natural ligand and voltage-gated ion channels. For example, the nicotinic acetylcholine and GABAA receptor/channel complexes will be studied, in addition to several voltage-gated ion channels, such as KShaw2, Kv1.2 and the bacterial voltage-gated channel, NaChBac. All of the work features rigorous attention to structural and energetic features underlying anesthetic interactions with protein, and now includes a new member focused on electrophysiologic characterization of function. Project 1 continues its focus on the binding event using photolabeling approaches, important new chemical tools and approaches are introduced as aim 1, and aim 2 deploys these approaches to discover anesthetic binding sites in both ligand-gated and voltage-gated ion channels. Project 2 anchors the biochemistry and biophysics to ion channel function through detailed electrophysiologic characterization of the ion channels being studied in the other projects, now including LGICs. Project 3 continues its synthesis of dynamics and structure using NMR spectroscopy in several of the same ion channels explored in the other projects, specifically, examples of ligand-gated channels and NaChBac. Several novel innovations in methodology have allowed better resolution in larger systems. Project 4 takes advantage of spectacular progress in computing resources and code to model the systems studied in the experimental projects, and serve as a hypothesis generating project. Importantly, an ability to independently calculate affinity in multi-site protens is an important innovation in this project. Project 5 represents a fusion of structure and function through cutting edge x-ray and neutron scattering experiments in immobilized, oriented lipid bilayers containing both native and minimally altered natural ion channels. The four experimental projects are supported by a modest administrative core and a protein expression core. This interdisciplinary program group has worked together extremely productively in the past, and now requests continued support to pursue these fundamental directions that will inform future drug improvement and discovery projects.